Wordpress Home page only works. The rest of the pages and post returns Nginx 404. CentOS Linux 7.6.1810

Question

I had successfully installed a wordpress site using the webmin but the problem is after i changed the permalinks settings of wordpress to '%postname%' the rest of the pages except the home page returns an error of Nginx 404. And to add on to that the links also added a 'index.php'. The current permalinks is like this (domainname.com/index.php/p=1000). I am a newbie to this server stuff and I don't really know what configurations should I change. Any help would be great. Thank you